From patchwork Mon May 17 13:59:07 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 440830 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EA976C433B4 for ; Mon, 17 May 2021 14:56:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CF89C60E0C for ; Mon, 17 May 2021 14:56:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240618AbhEQO5k (ORCPT ); Mon, 17 May 2021 10:57:40 -0400 Received: from mail.kernel.org ([198.145.29.99]:51038 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241772AbhEQOx4 (ORCPT ); Mon, 17 May 2021 10:53:56 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7A8AE619A3; Mon, 17 May 2021 14:24:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1621261458; bh=fxnDPLlPWYLf9/KzTkxHvikDC9lWN6ga0dBvtKr5d2I=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mn8mkZMHuj59bkLXOiQ+vfjRcmuir6Yui/QO15RbPntNlsEfUplb7G51owUHg1faN iNVMHvRW/Rz586uUti9y3qUuS2Ci1L4kV7ufMrgtdY4YgKGTBJgvqZpURuKUhkjczR aCffUlfitXt/6IYl87bfk0plPimFUyjMOgzWD/+o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com, Wolfram Sang , Wolfram Sang , Sasha Levin Subject: [PATCH 5.10 022/289] i2c: bail out early when RDWR parameters are wrong Date: Mon, 17 May 2021 15:59:07 +0200 Message-Id: <20210517140305.924508510@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210517140305.140529752@linuxfoundation.org> References: <20210517140305.140529752@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Wolfram Sang [ Upstream commit 71581562ee36032d2d574a9b23ad4af6d6a64cf7 ] The buggy parameters currently get caught later, but emit a noisy WARN. Userspace should not be able to trigger this, so add similar checks much earlier. Also avoids some unneeded code paths, of course. Apply kernel coding stlye to a comment while here. Reported-by: syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com Tested-by: syzbot+ffb0b3ffa6cfbc7d7b3f@syzkaller.appspotmail.com Signed-off-by: Wolfram Sang Signed-off-by: Wolfram Sang Signed-off-by: Sasha Levin --- drivers/i2c/i2c-dev.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/i2c/i2c-dev.c b/drivers/i2c/i2c-dev.c index 6ceb11cc4be1..6ef38a8ee95c 100644 --- a/drivers/i2c/i2c-dev.c +++ b/drivers/i2c/i2c-dev.c @@ -440,8 +440,13 @@ static long i2cdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) sizeof(rdwr_arg))) return -EFAULT; - /* Put an arbitrary limit on the number of messages that can - * be sent at once */ + if (!rdwr_arg.msgs || rdwr_arg.nmsgs == 0) + return -EINVAL; + + /* + * Put an arbitrary limit on the number of messages that can + * be sent at once + */ if (rdwr_arg.nmsgs > I2C_RDWR_IOCTL_MAX_MSGS) return -EINVAL;